The Rev Klaas Hendrikse can offer his congregation little hope of life after death, and he's not the sort of man to sugar the pill.

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The Exodus Church is part of the mainstream Protestant Church in the Netherlands

An imposing figure in black robes and white clerical collar, Mr Hendrikse presides over the Sunday service at the Exodus Church in Gorinchem, central Holland.

It is part of the mainstream Protestant Church in the Netherlands (PKN), and the service is conventional enough, with hymns, readings from the Bible, and the Lord's Prayer. But the message from Mr Hendrikse's sermon seems bleak - "Make the most of life on earth, because it will probably be the only one you get".

"Personally I have no talent for believing in life after death," Mr Hendrikse says. "No, for me our life, our task, is before death."

Nor does Klaas Hendrikse believe that God exists at all as a supernatural thing.

God is not a being at all... it's a word for experience, or human experienceRev Klaas Hendrikse

"When it happens, it happens down to earth, between you and me, between people, that's where it can happen. God is not a being at all... it's a word for experience, or human experience."

Mr Hendrikse describes the Bible's account of Jesus's life as a mythological story about a man who may never have existed, even if it is a valuable source of wisdom about how to lead a good life.

His book Believing in a Non-Existent God led to calls from more traditionalist Christians for him to be removed. However, a special church meeting decided his views were too widely shared among church thinkers for him to be singled out.

A study by the Free University of Amsterdam found that one-in-six clergy in the PKN and six other smaller denominations was either agnostic or atheist.

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Media captionKlaas Hendrikse: "You don't have to believe that Jesus was physically resurrected"

The Rev Kirsten Slettenaar, Exodus Church's regular priest, also rejects the idea - widely considered central to Christianity - that Jesus was divine as well as human.

"I think 'Son of God' is a kind of title," she says. "I don't think he was a god or a half god. I think he was a man, but he was a special man because he was very good in living from out of love, from out of the spirit of God he found inside himself."

Mrs Slettenaar acknowledges that she's changing what the Church has said, but, she insists, not the "real meaning of Christianity".

She says that there "is not only one answer" and complains that "a lot of traditional beliefs are outside people and have grown into rigid things that you can't touch any more".

Dienie van Wijngaarden, who's been going to Exodus Church for 20 years, is among lay people attracted to such free thinking.

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Some believe that traditional Christianity has too restrictive a notion of the nature of God

"I think it's very liberating. [Klaas Hendrikse] is using the Bible in a metaphorical way so I can bring it to my own way of thinking, my own way of doing."

Wim De Jong says, "Here you can believe what you want to think for yourself, what you really feel and believe is true."

Churches in Amsterdam were hoping to attract such people with a recent open evening.

At the Old Church "in the hottest part of the red light district", the attractions included "speed-dating".

As skimpily dressed girls began to appear in red-lit windows in the streets outside, visitors to the church moved from table to table to discuss love with a succession of strangers.

Professor Hijme Stoffels of the VU University Amsterdam says it is in such concepts as love that people base their diffuse ideas of religion.

"In our society it's called 'somethingism'," he says. "There must be 'something' between heaven and earth, but to call it 'God', and even 'a personal God', for the majority of Dutch is a bridge too far.

"Christian churches are in a market situation. They can offer their ideas to a majority of the population which is interested in spirituality or some kind of religion."

To compete in this market of ideas, some Christian groups seem ready virtually to reinvent Christianity.

They want the Netherlands to be a laboratory for Christianity, experimenting with radical new ways of understanding the faith.

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Media captionChurchgoer: "For me the service is very freeing"

Stroom ("Stream") West is the experiment devised by one church to reach out to the young people.

In an Amsterdam theatre young people contemplate the concept of eternity by spacing out a heap of rice grains individually across the floor.

"The difference from other churches is that we are… experimenting with the contents of the gospel," says Rikko Voorberg, who helps to run Stroom West. "Traditionally we bring a beautiful story and ask people to sit down listen and get convinced. This is the other way around."

Stroom focuses on people's personal search for God, not on the church's traditional black-and-white answers.

He believes that in a post-modern society that no longer has the same belief in certainty, there is an urgent need to "take God out of the box".

"The Church has to be alert to what is going on in society," he says. "It has to change to stay Christian. You can't preach heaven in the same way today as you did 2,000 years ago, and we have to think again what it is. We can use the same words and say something totally different."

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Staphorst, in the Dutch Bible Belt, has a by-law against swearing

When I asked Rikko whether he believed Jesus was the son of God he looked uncomfortable.

"That's a very tough question. I'm not sure what it means," he says.

"People have very strict ideas about what it means. Some ideas I might agree with, some ideas I don't."

Such equivocation is anathema in Holland's Bible Belt, among the large number of people who live according to strict Christian orthodoxy.

In the quiet town of Staphorst about a quarter of the population attends the conservative Dutch Reformed Church every Sunday.

The town even has a by-law against swearing.

Its deputy mayor, Sytse de Jong, accuses progressive groups of trying to change Christianity to fit current social norms.

"When we get people into the Church by throwing Jesus Christ out of the Church, then we lose the core of Christianity. Then we are not reforming the institutions and attitudes but the core of our message."

But many churches are keen to work with anyone who believes in "something".

They believe that only through adaptation can their religion survive.

The young people at Stroom West write on plates the names of those things that prevent earth from being heaven - cancer, war, hunger - and destroy them symbolically.